Even though the carbon compounds that accumulate in the engine are unwanted, carbon is very much a part of the internal combustion engine. This is due to the fact that lubricants and fuels used in the engine are carbon based compounds. The lubricant and fuel carbon bonds are formed with hydrogen and produce hydrocarbon chains. These hydrocarbon chains are refined from crude oil and contain various molecular weights. When these hydrocarbon chains are formed to produce lubricating oil they contain heavier, thicker petroleum based stock that have between 18 and 34 carbon atoms per molecule. Lubricating oil creates a separating film between the engine's moving parts that is used to minimize direct contact between the moving parts which decreases heat caused by friction and reduces wear, thus protecting the engine. When these hydrocarbon chains are made for fuel such as gasoline, they contain lighter petroleum based stock that have between 4 and 12 carbon atoms per molecule. Overall, a typical gasoline is predominantly a mixture of paraffins (alkanes), cycloalkanes (naphthenes), and olefins (alkenes). Fuel is blended to produce a rapid high energy release combustion event that propagates through the air in the combustion chamber at subsonic speeds and is driven by the transfer of heat. As the internal combustion engine is operated the fuel's energy is released in the combustion chamber. This occurs by a chemical change in the hydrocarbon chains. The heat from the ignition spark (gasoline) or from the compression (diesel) breaks the hydrocarbon chains so the bonds between the carbon and hydrogen are separated. This allows the carbon to bond with dioxygen (O2), and the hydrogen to bond with oxygen (O); thus changing the hydrocarbon chains to carbon dioxide (CO2), and water (H2O). However, if there is a lack of oxygen during the burning of the fuel then pyrolysis occurs. Pyrolysis is a type of thermal decomposition that occurs in organic materials exposed to high temperatures. Pyrolysis of organic substances such as fuel produces gas and liquid products that leave a solid, carbon rich residue. Heavy pyrolysis leaves mostly carbon as a residue and is referred to as carbonization.
As this carbon buildup creates tailpipe emission problems, drivability problems, and poor fuel economy, it is desirable to remove this buildup from the internal combustion engine. This carbon can be removed by engine disassembly and manual cleaning, however this is very time consuming and expensive. An easier, less expensive alternative is to remove this carbon buildup using chemicals to clean the engine. Over the years there have been numerous attempts involving the use of cleaning apparatus and chemicals to solve the problem of carbon buildup removal.
In U.S. Pat. No. 4,671,230 Turnipseed discloses a device that holds or contains a mixture of carbon cleaning solution and gasoline. The vehicle's fuel supply system is disabled from the engine and the invention is connected to the fuel delivery for the engine. The invention then supplies the engine with the pressurized cleaning solution as the engine is run. This cleaning solution is then delivered through the engine injectors. The problem with this method is that the cleaning solution is only applied to the intake valve and the immediate intake port area around the intake valve. The rest of the induction system remains uncleaned. Additionally, if the engine is that of a direct injection design, no intake cleaning will take place at all.
In U.S. Pat. No. 4,989,561 Hein discloses a device that connects to the throttle body of the engine. The device or metering block has an adjustment to increase or decrease the air flow into the engine. This air flow adjustment will set the air rate into the engine, thus bypassing the throttle plate control. The metering block also holds an electronic automotive style fuel injector that will deliver the cleaning chemical. The vehicle fuel system is disabled by unplugging the fuel injectors or fuel pump. If the vehicle is equipped with a Mass Air Flow (MAF) sensor an additional tube must be connected from the metering block to the MAF sensor. The throttle is then depressed and the engine is started and run on the cleaner solution that is pressurized and delivered to the engine. Once the cleaning solvent has been delivered and all of the chemical has been used, a second chemical is then added and the engine is run until all of this chemical has been used.
The problems with this method are threefold. The first problem is the complication and time to install the invention. The second problem is the engine Revolutions Per Minute (RPM) cannot be varied above the adjustment point of the metering block adjustment. The ability to change the RPM, which in turn changes the energy of the air flowing into the engine, is important. Since the energy of the air flow is carrying the chemical it will be necessary to raise the RPM and have a rapid throttle opening or snap throttle of the engine. This increased air flow will help prevent the chemical from puddling within the intake manifold as well as carry additional chemical to the carbon sites. The third problem occurs if the engine is equipped with Drive-by-wire. Drive-by-wire systems were first installed on vehicles as early as 1989 and by 2003 is standard equipment for most U.S. based vehicles. This system is a safety critical system where the Engine Control Unit (ECU) controls and monitors the throttle plate position. If the throttle plate position does not match the air flow rate commanded into the engine by the ECU the system is put into a default position. There are many different defaults that can be command by the ECU in order to maintain the air rate in to the engine. One such default could cause the engine to shut down by cutting the fuel, spark and air to the engine. Another default is accomplished whereby the throttle plate position is no longer controlled by the ECU but will allow the throttle plate position to be slightly opened by the default spring which will only allow the engine to run at about 1800 RPM. Additionally the fuel and spark can be turned on and off in order to control the air rate and RPM of the engine, which will cause severe damage to the catalytic converter. In yet another default the Drive-by-wire system will force the throttle shut when the expected air rate cannot be obtained.
In U.S. Pat. No. 6,557,517 B2 Augustus discloses a device that applies cleaning chemical into the engine through the spark plug hole. A single chemical cleaner is installed in the invention's multiple reservoirs in the main cylindrical body. The spark plugs are removed from the engine and an adapter is installed into each of the spark plug holes that are connected with hoses to the main cylindrical body. The main cylindrical body also contains a metering valve system that allows the chemical to be delivered directly into the cylinder without the engine hydrolocking or liquid locking. The cleaning chemical is put into the cylinder in order to clean the piston compression rings. In order to clean the piston rings the starter motor is bumped. Bumping means the starter is engaged for a very short time to move the piston up or down several inches. This piston movement when repeated multiple times with chemical cleaner applied to the piston ring will clean the carbon from the piston and piston ring.
The problem with this method is twofold. The first problem is the amount of time and knowledge required to install such a complicated device. The second problem is the only carbon removal that is accomplished is in the combustion chamber. The induction system or intake tract which can include; the throttle body, throttle plate, intake plenum, intake manifold, intake charge valve, intake runners, intake port, and intake valve are not cleaned at all by the invention.
In U.S. Pat. No. 6,530,392 B2 Blatter discloses a device that applies cleaning chemical into the engine through the vacuum port. The base of the device holds a can of chemical cleaner and has a means to adjust the flow rate of the cleaner that can be observed through a sight glass. The base is connected to the nozzle with a tube. The nozzle has a hole drilled at a 90 degree angle that will bleed air from the atmosphere into the discharge. The nozzle is connected to the engine vacuum hose on the engine's intake system. The engine is then started and run where the low pressure created by the running engine pulls the cleaner into the intake tract. The cleaner can be adjusted by turning the adjustment screw while watching the flow through the sight glass. The entire can of chemical is delivered in one continuous application to try to clean the engine. As the cleaner is pulled through the discharge nozzle air from the atmosphere moves through the air bleed, located in the discharge nozzle, where it is mixed with the chemical cleaner. This air bleed breaks up the liquid cleaner into droplets as it is delivered into the intake tract.
The problem with this design and its method of use is the droplet size is not consistent as is illustrated in Applicant's FIG. 10. As the engine is running the droplet sizes are both small and large without being held constant; with the larger sizes moving slower than the smaller droplet sizes in the air flow, they tend to congeal together making much larger droplets. As the liquid is broken up into droplets by the air bleed, the air to cleaner ratio is constantly changing. This allows the creation of droplets that are too large to be transported by the air flow making it difficult for the chemical to reach the carbon sites on the intake runner top and sides as well as the intake port top and sides. Thus, only some carbon is cleaned and some remains. Additionally there is very little vacuum under cranking and snap throttle conditions, so no chemicals can be pulled from the reservoir and be delivered to the induction system under these conditions.
As can be seen the prior art has many limitations. These limitations pose significant problems when cleaning the induction system. What is needed is the means to quickly and easily remove the carbon from the internal combustion engine. The present invention accomplishes this.